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SinterCast and the Environment

SinterCast contributes to the environment directly and indirectly. In the foundry, the improved efficiency of the SinterCast-CGI technology reduces energy consumption; reduces CO2 emissions; and reduces the demand for raw materials. On the road, CGI enables the use of more efficient downsized engines, improving fuel economy and reducing CO2 emissions. Scroll down to learn more about how the SinterCast technology contributes to the environment: in the foundry; in passenger vehicles; in commercial vehicles; in clean diesel engines; and in life cycle analyses compared to aluminium engines and electric vehicles.

Foundry EfficiencyImproved process control reduces the number of rejected (scrap) castings in the foundry. Less scrap means fewer castings need to be re-melted and re-cast. The energy needed to melt cast iron is approximately 10,000 MJ per tonne. For a foundry producing one million Engine Equivalents per year, with a mould yield of 65%, the annual energy demand for melting is approximately 800 million MJ, corresponding to more than 35,000 tonnes of coal per year. Every 1% of scrap reduction reduces the coal demand by over 350 tonnes per year – approximately 1,000 tonnes of CO2 for every one million Engine Equivalents. SinterCast helps the foundry to be right-first-time.

Foundry Weight ReductionThe increased strength of CGI allows the weight of cylinder blocks to be reduced by 10-20% compared to a conventional cast iron cylinder block. Less weight means less metal melted in the foundry. For a foundry producing one million Engine Equivalents per year, 15% weight reduction provides an annual savings of 7,500 tonnes of castings, corresponding to approximately 10,000 tonnes of liquid iron. This reduction in liquid metal demand corresponds to a saving of approximately 100 million MJ of electricity, 4,500 tonnes of coal, and 10,000 tonnes of CO2 per year.

Passenger VehiclesThe increased strength of CGI allows engineers to reduce weight while increasing the combustion pressure, resulting in more power per litre. Smaller CGI engines can replace larger engines while providing similar performance. This downsizing can provide weight reduction of approximately 25 kg in a passenger vehicle engine. For passenger vehicles, every 100 kg of weight reduction provides a fuel saving of approximately 0.2 litres for every 100 km driven. The 25 kg weight saving corresponds to 100 litres of saved fuel over the 200,000 km lifetime of a vehicle, providing a reduction of approximately 250 kg of CO2 per vehicle.

Commercial VehiclesWeight reduction in commercial vehicles enables increased payloads; reduced vehicle-miles; and, improved fuel economy. Every 100 kg of weight reduction improves commercial vehicle fuel economy by 0.1%. For a typical 12L engine, with fuel consumption of 40 litres per 100 km, the use of SinterCast-CGI can reduce the weight by approximately 100 kg, yielding fuel savings of approximately 0.04 litres for every 100 km. With typical annual mileage of 250,000 km, the weight saving of 100 kg corresponds to a fuel saving of approximately 100 litres of diesel fuel per year – a reduction of more than 250 kg of CO2 per year and 2,000 kg of CO2 over the typical lifetime of a commercial vehicle.

Cast Iron vs AluminiumThe production of primary aluminium from ore requires approximately five times more energy than the mining and smelting of iron. The foundry processing of aluminium also requires more energy than cast iron. To provide a net benefit to society, the reduced weight of the aluminium engine must provide fuel savings that are larger than the extra energy contained in the raw materials plus the extra energy consumed to produce the cylinder block. For a typical 1.6 litre four-cylinder engine, the weight difference between an aluminium engine and a cast iron engine is usually less than 10 kg. Weight reduction in passenger vehicles saves approximately 0.2 litres of petrol (0.15 litres of diesel) for each 100 km driven and 100 kg of weight saved. Considering the 34.2 MJ/litre energy content of petrol (38.6 MJ/litre for diesel), a 10 kg lighter aluminium engine must drive approximately 200,000-500,000 km before the initial energy penalty is recovered. This is beyond the life of most vehicles.

For V-type engines, CGI engines are often lighter than aluminium engines. For these engines, it is impossible for aluminium to provide a CO2 payback to society.

Vehicle Life Cycle

Today’s legislation focusses only on the tailpipe emissions during the on-road use phase, with no regard for the energy consumption or emissions during the manufacture of the vehicle; the provision of the fuel (or electricity); or, the end-of-life recycling. The full environmental impact of electric vehicles must include the additional energy needed to manufacture the batteries and the emissions associated with the generation and provision of the electricity used to charge the batteries.

For a typical mid-size vehicle, battery manufacturing adds 15% to the CO2 emissions associated with vehicle manufacture and assembly. For a full-size vehicle, the larger battery pack can add 60-70% to the vehicle CO2 emissions. Recent life cycle studies [1-3] indicate that the total life cycle CO2 of diesel vehicles and electric vehicles is not significantly different, and that electric vehicles can often have higher life cycle CO2 emissions.

The impact of the electrical energy source on the environmental friendliness of battery vehicles is also consider the effect of the life cycle emissions on mortality rates. The majority of the electric power supply in the main car-buying regions of continental Europe, China, India and the United States is derived from fossil fuels. The conversion of these fuels to electricity emits CO2, NOx, particulates and toxins, including lead and mercury. A 2014 University of Minnesota study published in the Proceedings of the National Academy of Sciences estimated that, if 10% of the vehicle miles travelled in the US in 2020 were driven by diesel cars, 870 deaths would be incurred due to air quality. However, if 10% of the vehicle miles travelled in the US in 2020 were driven by battery electric vehicles, powered by the 2020 national grid, 1,610 deaths would be incurred due to air quality. SinterCast encourages a holistic approach to legislation, considering life cycle emissions and favouring vehicles that provide the best overall contribution to society.

Tessum et al. University of Minnesota: Life cycle air quality impacts of conventional and alternative light-duty transportation in the United States. Proceedings of the National Academy of Sciences, USA. 30 December 2014

Clean Diesel

Diesel fuel contains approximately 12% more energy than petrol and diesel engines have a higher thermodynamic efficiency than petrol engines. The net result is that diesel engines are 20-30% more fuel efficient than petrol engines.

Diesel engines contribute to reduced CO2 emissions. However, the political debate has evolved from CO2 and climate change toward NOx and air quality. Several major Tier I suppliers to the automotive industry have presented solutions to reduce diesel NOx emissions below legislated levels. These solutions are generally based on combining established treatment technologies to sequentially reduce the NOx. These technologies can enable continued use of diesel engines in larger SUV, luxury vehicles and pick-ups, where the benefits are greatest, and where drivers seek the drivability, range and fuel economy offered by diesels. The cost of these technologies may be too high for lower cost vehicles, reducing the diesel take rate in small vehicles.